Alcohol begins to takes its course on the human body virtually the instant it’s ingested, however the effects are not “felt” until it reaches the brain. At this point in the process, the brain is literally infiltrated by alcohol. A membrane called the blood-brain barrier (BBB) is a network of capillaries in the human brain designed to block chemicals from getting into the rest of the brain and the body. Alcohol however, gets through due to its small molecular structure (among other small molecule bad-for-you agents like nicotine and caffeine). So, the brain gets bombarded with an agent it’s not designed to be exposed to, let alone filter, and then what? Well. Here’s what:

The frontal lobes are the area of the brain responsible for judgment and impulse control, as well as social and sexual behavior, and ability to reason. When intoxicated, a person’s judgment can stray from typical rationality. Behavior is skewed so much so, that a person who is intoxicated can be found participating in activities (sexual, social, or otherwise) they would not ordinarily choose to be involved in. Loud, boisterous demeanor that is often associated with alcohol use occurs in the frontal lobe as the brain abandons its ability to reason and loses its inhibitions.

The temporal lobe, an auditory processing center in which parts of language, speech, sounds, and vision are computed, is where we begin to see the most obvious effects of alcohol on the brain. The intoxicated brain loses its command over verbal communication, slurring speech in attempted conversation. The ability of the intoxicated person to hear and comprehend his own thoughts and speech as well as those of others, becomes obstructed, changing his position in a social setting. The hippocampus is a part of the brain found in the temporal lobe. Though its exact function is not clear, it is thought that the hippocampus contributes to the creation of memories. The alcohol’s contribution to the hippocampus hinders the formation of new memories, although does not seem to have a proven effect on those already created. This explains how a college student may remember his home address from a year before, but not recall the details the next day from the night before spent heavily drinking.

These levels of brain function (or lack thereof) when intoxicated depend entirely on the concentration of alcohol in the blood. The body can get rid of a very small percentage of the alcohol through sweat, tears and breath, but this leaves the rest to be metabolized by the liver. The liver can only metabolize a certain percentage alcohol in one hour’s time, regardless of the consumption amount. This rate of metabolism directly affects the blood alcohol content (BAC), which directly affects how “drunk” the subject will get. Several factors contribute to this including gender, weight, food consumption, and age. Women, for example, have less water in their bodies than men, thus the concentration of alcohol in a woman’s blood may be more than a man who drank the same kind and number of drinks. The legal BAC limit for driving a vehicle in the United States is .08%. It is a percentage, so this scale changes from person to person.

The damaging affects alcohol inflicts on the brain - impaired judgment, blurred vision, irrational behavior - could translate into disaster when coupled with driving. Impaired judgment and poor vision slow reaction time and decision-making, both crucial components to maintaining safe vehicle operation. Irrational thinking and obnoxious behavior could result in speeding, erratic driving, and road rage. Drunk driving causes accidents that result in injuries, car damage and loss, and even death. These incidents are responsible for killing thousands per year, not to mention the costs for court fees, insurance, and medical bills of the injured.
There is considerable damage being done - to our brains, to our cars, to our people - all in the name of alcohol. The thing is, it’s 100% preventable…